The ultimate objective of the proposed research is to conduct a series of coordinated studies designed to characterize in detail and quantitate in terms of central and peripheral input mechanisms the control of the thermal regulatory effector responses of primates when exposed to a wide range of temperature conditions. To quantitate and differentiate the basic changes in thermoregulatory function, centrally in the hypothalamic center and peripherally at the level of the effector systems i.e., sweat gland, blood vessels, hormones, etc., associated with the natural adaptive processes associated with long term cold and heat exposure. Furthermore, quantitation of thermoregulatory changes associated with disease conditions such as fevers will also be investigated.